Both this post and your flame sensor post are in the wrong forum. This one is for residential owners. You should be posting in tech to tech.

 

one cause is an improperly pitched vent pipe. If the pipe doesn't have the proper pitch back towards the furnace, it will fill with water while the furnace is running. As soon as it shuts off, the water rushes back towards the furnace, overloads the in-line drain fitting, and ends up in the inducer.

 

I also heard of a improperly pitched secondary heat ex. If its not leaned forward. Have you ever seen that?

 

If the drain system is partially plugged it can slowly back the water up into the secondary, shut down the furnace, and drain away the secondary leaving water in the inducers without a drain, possibly.

 

I saw a new furnace once that didn't have a trap in the drain line and when it would initially fire up it would be just fine, but without a trap the negative pressure of the inducer assembly would suck back through the drain line and let water build up in the inducer until it couldn't keep the pressure switch closed, then it would kick out it would drain some of the water and relight and repeat.

 

If water in the vent motor is an issue and everything seems correct, you can cut a 3x3x1½ (or 2x2x1½) *T* into the vent pipe (on the horizontal), install a 1½ x ¾ female adapter into the *T* then a ¾ male x ⅜ hose barb and use ⅜ ID hose with a loop in it for a 'trap' and drain it to the condensate pump or whatever drain is handy.

This will end any further problems with condensation in the vent motor.

p.s. the ⅜"I.D. hose with the pig tail (loop) as a trap is important, DO NOT just park a hose on the *T* and let it hang. You must have some type of *P*trap on that hose

 

I am going to this call right now and of I see that this is a good system to try this on I will. I'll let you know how it goes. I really appreciate all of the responses

 

On some units, you can drill a hole at the bottom of the combustion blower and put a hose there going to the drain but make sure it is looped. I believe it is a 3/8 hose

 

seriously? your going to drill a hole in the vent motor housing and install a hose? how would you seal it? Silicone?
If there wasn't a hose there to start with, from the factory, then I would not be changing the system design without factory approval.

If your hose leaks on to the circuit board.......your screwed

 

Are these water problems usually just a poor venting issue? If the combustion is okay

 

depends, could be the vent pipe is running through a cool area, but not freezing and the pipe is at it's maximum length. Your going to get water.

Could be there is a lot of moisture in the gas, BTU content changes on a daily basis, so does moisture content.

Could be the furnace is not level?

Could be to many *T*'s in the vent pipe (Restrictions)

or it could be the vent pipe is virtually flat, with no slope

 

Like I said (on some units)lennox, g26 there is a spot for the hole to be drilled,it comes with a kit, you seal in with a hose clamp and you dont have to worry about water on the board. If someone has not worked on one they would think it is crazy to.

 

sorry dude, my bad. I thought you were just going to drill a hole in the damn thing :couchhide:

so the G26 comes with a 'boss' on the vent housing you drill out or knockout and your good-to-go?

 

Any time ive had moisture in an inducer motor/ heat exchanger, Its has been incorrect vent pipe sizing. (Too big) if your vent is to big it will condesate and run down into your inducer. If your furnace has a 3in exaust it needs to be ran 3in the whole lengh of the vent pipe not 3in to 4 or 6in for example. Also check if the right rain cap is installed

 

I searched it on google and that was what it told me. I can't say I spoke to a rep

 

Propane combusts and leaves behind CO and H20.

 

plugged trap or no trap
plugged drain

 

Installing a drain "T" in the vent pipe is common among On Demand water heaters. I've seen these before, Rinnai factory kit. Difference with this is they were correcting the issue of natural condensate running back to the unit only the configuration would have it landing on the burner rack. As the condensate would evaporate it left behind all the sediment which would clog all the burner orifices. (a real pain to clear out)


Water in the inducer motor (or impeller housing).
Every time I have seen this it's been because of improper drainage. Whether that be the vent pipe, no trap, or pitch of the unit (not so much pitch of the unit).

I would lay bet that after reading everyone's posts I'm going to throw this one out there...
What position is the furnace in? Is the inducer assembly setup for vertical and the unit is mounted horizontal? Maybe the little bit of condensate isn't making it's way to the drain for a simple reason.

I don't remember reading the OP mention that unit was locked out on a fault.
(manual reset pressure switch issue)

~smoke~

 

I went on one yesterday, Inducer assembly full of water and the motor couldn't even turn against all the water. Clear the drain line of crud and drain the assembly and all is well.